One conventional envelope transport and insertion machine includes U.S. Pat. No. 4,604,849 issued on Aug. 12, 1986, and assigned on its face to Bell & Howell, shown in FIG. 1. The entire disclosure of U.S. Pat. No. 4,604,849 is hereby incorporated by reference herein, in its entirety. FIG. 1 shows a stack 36 of envelopes positioned on table 22 at a location where envelopes may be pulled from the bottom of the stack by a feeder mechanism (not shown) and then deposited on an intermittently operating chain drive 26 which carries the envelope to a stuffing location 39. Grippings 38 are attached to the envelope drive chain 26 at periodic locations. As the chain 26 intermittently moves an envelope in direction A to stuffing position 39, the envelope flap is opened by a rotating suction cup assembly 40, which holds the envelope flap in a captured or hold down position. The chain 26 then moves the envelope to its correct stuffing position, where its flap is held down by means of a plate 42 under which the flap extends. Then a pivoted arm 44 moves downward where vacuum sucker cups 46 attach themselves to the back side of the envelope. Next, the pivoted arm 44 raises the sucker cups 46 to hold open one side of the envelope, the flap being held down by plate 42. When the stack of inserts are deposited at stuffing station 66, kickers 50, 52 push the stationary inserts over plate 42 and into the envelope being held open by the suckers 46.
Conventional envelope transport and insertion machines also include, for example, U.S. Pat. No. 5,706,636 issued on Jan. 13, 1998 and assigned on its face to Böwe Systex AG, shown in FIG. 2. The entire disclosure of U.S. Pat. No. 5,706,636 is hereby incorporated by reference herein, in its entirety. In FIG. 2, envelopes 20 are pulled from a stack 1 by a pull-off device 2 and are transferred to a conveyor 5. Conveyor 5 is a revolving toothed belt provided with a plurality of grippings 17 configured to revolve around a horizontal axis. The conveyor 5 forms, with its upper strand 19, a horizontal conveying plane 13. A space between the two conveying planes 12, 13 includes a spreading device 7 for envelopes 20 and a link chain 10 configured to revolve in a vertical conveying plane. The spreading members 9 engage the envelopes along the conveying plane 13 and then raise them into the level of the conveying plane 12 of the conveyor 6 for envelope contents 21.
Another conventional envelope transport and insertion machine includes U.S. Pat. No. 5,954,323 issued on Sep. 21, 1999, and assigned on its face to Bell & Howell Mail Processing Systems, shown in FIGS. 3(a)–3(b). The entire disclosure of U.S. Pat. No. 5,954,323 is hereby incorporated by reference herein, in its entirety. FIGS. 3(a)–3(b) show insert packets 63 transported to an insertion station 64. Vacuum cups (not shown) remove an envelope from a stack of envelopes 67 and release it to an envelope conveying mechanism (not shown). As the envelope is conveyed, the envelope is opened by an envelope flap opener and the open flap is engaged and held in an open position by hold-down bar 72 until the envelope reaches the insertion station 64, whereupon an envelope flap gripping pinching foot (not shown) may be driven against the envelope flap to secure the envelope flap against an insertion plate 75 for the insertion process. An envelope opener or puffer (not shown) fills the envelope with air and envelope insertion fingers 79 are inserted to keep the envelope open. With the envelope opener and the insertion fingers holding the envelope fully open, a pusher fork 68 transfers insert package 63 into the envelope. Following insertion, the leading edge of the filled envelope is thereafter gripped by a dog on a chain conveyor (not shown) and transported for continued processing.
Still another conventional envelope transport and insertion machine described in U.S. Pat. No. 6,168,008 issued on Jan. 2, 2001 and assigned on its face to Bell & Howell GmbH of Friedberg, Del., is shown in FIG. 4. The entire disclosure of U.S. Pat. No. 6,168,008 is hereby incorporated by reference herein, in its entirety. In this publication, a handling station includes an intermittently driven, endless, rotating gripping chain 107 having gripping claws 108 mounted thereto. Below the upper reach of the gripping chain 107 are guide elements or cam elements 109 mounted to the frame structure and cam elements cooperate with cam follower fingers 110 of the respective gripping claws 108. During rotation of the gripping chain 107, such that as the cam follower finger 110 passes the fixedly mounted cams or ramps 109, the cam action opens the gripping claws 108 against a spring bias. The gripping claws 108 serve for gripping the leading edge of a respective envelope 90 which is pulled by the respective gripping claw 108 within a guiding channel provided in the region of the gripping chain 107, into a position, in which inserting of the document or the set of documents 105 takes place. In a corresponding position the gripping claw 108 is reopened after the envelope has been filled so that the filled envelope is delivered.
In another conventional envelope transport and insertion machine, described in U.S. Pat. No. 6,199,348 issued on Mar. 13, 2001 and assigned on its face to Bell & Howell Mail and Messaging Technologies Company of Durham, N.C., is shown in FIGS. 5(a)–5(b). The entire disclosure of U.S. Pat. No. 6,199,348 is hereby incorporated by reference herein, in its entirety. In this publication, the envelope packing assembly 104 comprises a packing prompter 106 for urging each consecutive envelope from the top of the second buffer stack 92 toward a threading means 103 and a packing plate 111. Packing prompter 106 removes an uppermost envelope from the second buffer stack 92 and urges it toward the threading means 103. Packing prompter 106 comprises a first and second roller 112,114. First roller 112 rests atop the second buffer stack 92 to provide the initial force to each envelope 4. The second roller 114 then guides the displaced envelope to the bridge conveyor 138, which comprises two rollers with a belt configured therearound such that envelopes leaving the packing prompter 106 are guided onto threading roller 103.
In still another conventional envelope transport and insertion machine described in U.S. Pat. No. 6,240,710 issued on Jun. 5, 2001 and assigned on its face to Bell & Howell Mail; Messaging Technologies Company of Durham, N.C., is shown in FIGS. 6(a)–6(b). The entire disclosure of U.S. Pat. No. 6,240,710 is hereby incorporated by reference herein, in its entirety. An envelope is positioned in a pre-stage area upon deck plate 28 and is then moved out of the pre-stage area by rotation of D-rollers 54. Flipper rollers 58 rotate to bias the flap up ramp 70. The D-rollers 54 move the envelope over stage rollers 62. FIG. 6(a) shows that discharge plate 78 is lowered such that the envelope is clamped between stage roller 62 and stage idler roller 61. Rotation of stage roller 62 then moves the envelope up spring guides 68 and onto thread roller 80. FIG. 6(b) shows discharge plate 78 is raised to nip the envelope flap between the thread roller 80 and the packing plate 82. Rotation of thread roller 80 thus threads the envelope onto the packing plate 82.
However, despite the advances realized by the aforementioned envelope transport and insertion machines, significant improvements can still be realized in transportation of envelopes from a staging area to an envelope stuffing area at a high rate of speed while maintaining envelope registration during such transport and assuring that the envelope is aligned properly in the stuffing area. Moreover, significant improvements can be realized in the speed at which envelopes are transported and stuffed or filled.